1. Field of the Invention
The present invention relates to a semiconductor mounting structure, and more particularly to a flip chip semiconductor mounting structure.
2. Description of the Related Art
A conventional flip chip semiconductor mounting structure is illustrated in FIG. 1. A semiconductor chip 1 with bumps 3 is bonded on a substrate 1. The bumps 3 are bonded and electrically connected with mounting pads 5 which have been provided on a bonding surface of the substrate 1. A solder resist 9 is further provided over the bonding surface of the substrate 6 except for the mounting pads 5. The bumps 3 form a space between the semiconductor chip 1 and the substrate 6. A sealing resin 4 is provided in the space defined between the semiconductor chip 1 and the substrate 6.
FIG. 2 is a plane view illustrative of a semiconductor chip 16 adhered via an insulation material such as a glass material on a lead frame without use of die bonding. An insulation oxide film is formed over a surface of the semiconductor chip 16. A ground aluminum wiring 13 is provided over the insulation oxide film wherein the ground aluminum wiring 13 extends over peripheral portions of the semiconductor chip 16. Namely, the ground aluminum wiring 13 extends along each sides of the semiconductor chip 16 to encompass a center portion of the semiconductor chip 16. The insulation oxide film underlying the ground aluminum wiring 13 has a large number of contact holes 15 aligned along the ground aluminum wiring 13. Electrode pads 17 are aligned along the inside of the ground aluminum wiring 13. Ground electrode pads 14 are also provided in the alignments of the electrode pads 17. The ground electrode pads 14 are connected to the ground aluminum wiring 13. It is possible that a bottom surface of the semiconductor chip 16 is adhered via an insulation material such as glass material onto the lead frame. In this case, the ground electrode pads 14 are electrically connected via bonding wiring to external leads for grounding the package so that the substrate of the semiconductor chip 16 is grounded. The ground electrode pads 14 are connected to the ground aluminum wiring 13. This ground aluminum wiring 13 is further electrically connected via the contact holes 15 to the substrate of the semiconductor chip 16. As a result, the substrate of the semiconductor chip 16 are grounded with stability.
The semiconductor chip 16 may be mounted onto the substrate by use of not only the wire bonding but also bumps, for example, the flip chip bonding.
If the flip chip bonding is used to bond the semiconductor chip via bumps onto the mounting pads of the substrate as illustrated in FIG. 1, then the substrate of the semiconductor chip is grounded only via the bumps. Since, however, the ground resistance is large, it is difficult to keep the substrate of the semiconductor chip 1 at the ground potential with stability.
On the other hand, if the semiconductor chip is mounded on the substrate as illustrated in FIG. 2, then it is necessary to provide the ground aluminum wiring on the peripheral region of the semiconductor chip. It is also necessary to further provide a large number of contact holes for contacting the ground aluminum wiring to the substrate. It is furthermore necessary to provide bonding wires for connecting the ground electrode pads 14 to the external leads. For those reasons, the semiconductor chip area is caused to be enlarged. The assembling cost and the mounting cost are caused to be increased.
In the above circumstances, it had been required to develop a novel flip chip mounting structure for allowing stable operations of a semiconductor chip.